Is the Power Spectrum of Electromyography Signal a Feasible Tool to Estimate Muscle Fiber Composition in Patients with COPD?

Antonino Casabona,Cristina Russo,Lucia Malaguarnera,Claudia Crimi,Matteo Cioni,Maria Stella Valle,Nunzio Crimi,Luca Laudani

doi:10.3390/jcm10173815

Abstract

A greater proportion of glycolytic muscle fibers is a manifestation of skeletal muscle dysfunction in Chronic Obstructive Pulmonary Disease (COPD). Here, we propose to use the spectral analysis of the electromyographic signal as a non-invasive approach to investigate the fiber muscle composition in COPD. We recorded the electromyographic activity of Rectus Femoris (RF), Vastus Lateralis (VL), Vastus Medialis (VM) and Biceps Femoris (BF) muscles, in ten patients and ten healthy individuals, during non-fatiguing, flexion–extension leg movements. The mean (MNF) and median frequencies (MDF) were calculated, and the most common profiles of electromyographic power spectrum were characterized by using the principal component analysis. Frequency parameters showed higher values in patients with COPD than in the control group for the RF (+25% for MNF; +21% for MNF), VL (+16% for MNF; 16% for MNF) and VM (+22% for MNF; 22% for MNF) muscles during the extension movements and for the BF (+26% for MNF; 34% for MNF) muscle during flexion movements. Spectrum profiles of the COPD patients shifted towards the higher frequencies, and the changes in frequency parameters were correlated with the level of disease severity. This shift of frequencies may indicate an increase in glycolytic muscle fibers in patients with COPD. These results, along with the non-fatigable nature of the motor task and the adoption of a non-invasive method, encourage to use electromyographic spectral analysis for estimating muscle fiber composition in patients with COPD.

Highlights

Dysfunction of skeletal muscles is a relevant manifestation of Chronic ObstructivePulmonary Disease (COPD) that affects motor function and limits the ability to carry out habitual activities of daily life [1,2,3,4,5]
During the extension movements most of the surface electromyography (sEMG) activity occurred in Rectus Femoris (RF), Vastus Lateralis (VL) and Vastus Medialis (VM) muscles (Figure 2A), with the group of patients showing significantly lower levels of sEMG area with respect to the control group (RF: p = 0.026; VL: p = 0.043; VM: p = 0.047)
The results of the present study show that a non-fatiguing motor task is effective for identifying and quantifying the increase in frequency range of the sEMG power spectrum, along with the concomitant decrease in sEMG magnitude, in persons with Chronic Obstructive Pulmonary Disease (COPD) compared to a group of healthy individuals

Summary

Introduction

Dysfunction of skeletal muscles is a relevant manifestation of Chronic ObstructivePulmonary Disease (COPD) that affects motor function and limits the ability to carry out habitual activities of daily life [1,2,3,4,5]. As the severity of COPD increases over time, peripheral skeletal muscles show several biochemical and histological alterations consisting of a reduction in cross-sectional area [6,7], enzymatic and mitochondrial abnormalities [8] and changes in the composition of the muscle fiber types [9,10,11]. These alterations contribute to a progressive decrease in muscle strength and endurance, especially in the lower limb muscles [12,13]. In the case of studying the fiber composition of a muscle, recording the surface electromyography (sEMG) signal could be a non-invasive, valid alternative method [14,15]

Methods

Results

Discussion

Conclusion